"xe-daemon" in TrueNAS core domU writes to non-existent nodes of a vanilla Xen dom0 (ie. not XAPI-based)

At this time there is insufficient information to proceed with the investigation. If at any time additional debugging information is supplied this ticket may be reopened for evaluation.

If you use the link in the first comment to upload your files, they are only accassible by iX developers. The developers get many tickets every day, so they typically do not look into tickets unless they have a debug attached.

Wait, what ? That’s an INSANE amount of private information ! Sorry but I’m not comfortable with sharing that much.
I know that you have procedures and all, but why on earth would you need all that info for this kind of bug report ?!

Thank you for your report, !

Please use the link in the system-generated message below to attach a system debug file. Link to this ticket after you upload the file and before you click Save.

To generate a debug file on TrueNAS CORE, log in to the TrueNAS web interface, go to System > Advanced, then click Save Debug and wait for the file to download to your local system. In TrueNAS SCALE, this option is in System Settings > Advanced.

Sorry, there are a few mistakes in the bug report, and analyzing the files I found a few other problems/remarks.

About “xenstore-write-cached attr/PVAddons/*" in “xe-update-guest-attrs“ (lines 175-180), it works reliably and is not related to the NICs nodes as wrongly written previously …
Although, why updating those values each minute ? AFAIK they can only change during a system update, and FreeNAS forces a reboot after an update anyway.
Same for ballooning, shouldn’t :

be only executed once, when “xe-daemon“ starts ?
So, moving lines 172-180 to “xe-daemon“ ? I know the values won’t get updated if they didn’t change, but some code is still executed. Or is it because “better safe than sorry” ?

In “xe-update-guest-attrs“, concerning NICs values in xenstore, as written (in a bad way) in my previous comment, it does not take into account VLAN interfaces :

Two solutions, either use :

or when creating interfaces, include xn with vlan, like “xn_vlan0“ or similar.
In any case, you would then also need to edit all the “sed 's/xn/eth/g'“ and alikes.

Also, and if correctly reading the manpage, the paths used are wrong.
The paths written to dom0 are :

• “attr/$DEV_ID” when it should be “attr/vif/$DEV_ID“

• “attr/$DEV_ID/ip“ when it should be “attr/vif/DEVID/ipv4/INDEX = IPV4_ADDRESS”

Talking about paths, I think the “PVAddons/*” nodes should be written to “data/” (like meminfo*, os_* and updated), and not to “attr/”, which seem reserved for vifs only.

Last, about domid. In “xe-update-guest-attrs“, it tries to :

But on my system, there’s no “unique-domain-id“ node (result: “xenstore-read: couldn't read path /local/domain/3/unique-domain-id“). So neither the comparison to detect domain change afterwards does work, nor is it written the first time, breaking subsequent calls.
Is it my dom0 which does not create the expected node, or should the “unique-domain-id“ be removed from this line ?
(From the docs, I thought you meant to use “/local/domain/${domid}/vm“, which returns “/vm/[A_GUID]“, but it’s not guest readable).

Side notes :

• should I update the bug report title (if I can), as finally I spotted more than “writing to non-existent nodes” ? ^^

• should I post this bug somewhere else ? Note that I already posted on xen-devel (got an answer today so it may not be stalled).

Thanks, I hope this report is now correct.